Topology identification in distribution network with limited measurements

Abstract

A statistical technique is used to estimate the status of switching devices (such as circuit breakers, isolator switches and fuses) in distribution networks, using scares (i.e., limited or non-redundant) measurements. Using expected values of power consumption, and their variance, the confidence level of identifying the correct topology, or the current status of switching devices, is calculated using any given configuration of real time measurements. Different topologies are then compared in order to select the most likely topology at the prevailing time. The measurements are assumed as normally distributed random variables, and the maximum likelihood principle or a support vector machine is applied.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61 / 515,019, filed Aug. 4, 2011, the contents of which are hereby incorporated by reference herein.FIELD OF THE INVENTION[0002]This invention relates generally to power distribution systems, and more particularly to methods, systems and computer readable media for identifying a network topology created by open and closed switching devices, based on historical data and on sparse real-time measurements in the network.BACKGROUND OF THE INVENTION[0003]The concept of electric power system state estimation was initially applied to transmission networks to estimate node voltages, generator power outputs, load demands, and branch power and current flows at a given point in time based on real-time telemetered measurements. This application has generally assumed imperfect but highly redundant measurements, as well as exact power system model topology and electrical p...

AI Technical Summary

Benefits of technology

The present disclosure provides a method for identifying the status of switch devices in a distribution network with multiple buses. It involves creating a probability model for power injections at each bus based on historical data, and then selecting the network topology that is most likely to produce the real-time sensor measurements based on the probability model. The method uses an optimization approach to select the most likely network topology, which can help to improve the accuracy of identifying the status of switch devices in the network. The computer-usable medium includes the computer-readable instructions for the method.

Problems solved by technology

Undetected switching device status errors during estimation show up as analog measurement errors in the solution, which are difficult to distinguish from actual analog measurement errors.

For many distribution networks, however, the measurement redundancy is so low that the first and often only indications of an outage are telephone calls from customers reporting loss of supply.

In the mostly radial topologies of a distribution network, the opening of a normally-closed switching device generally results in some loss of electric power supply.

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